And I would like to add always keep your EOBT updated according to Eurocontrol requirements. Any change to you EOBT for a period greater than 15 min before or after your EOBT must be communicated.
With an EOBT 0900 in an aerodrome with 10min taxitime a CTOT of 0910 is considered a No delay. But if you are ready for startup at 0835 (meaning roughly a 0840 off blocks) then you will perceive the CTOT as a delay.
Always keep in mind that a REA message will be rejected automatically by the NM if it is received earlier than EOBT-15min. I think that is an incentive for AOs to keep their EOBTimes updated.